Universal dumpster

ABSTRACT

The invention is a universal dumpster adapted for use with both conventional front loading and roll-off refuse collection trucks. A universal dumpster according to this invention includes a floor, a pair of side walls, and a pair of end walls. The floor, side walls and end walls together define an interior compartment for collecting and containing solid waste. Sleeves rotatably mounted to the side walls engage the lifting arms of a front loading truck. At least one of the end walls includes a door that is movable between a first fully closed position and a second fully opened position for depositing solid waste into the dumpster and discharging the solid waste from the dumpster. The rotatable sleeves reduce the forces exerted on the lifting arms of the front loading truck. Accordingly, the capacity of the dumpster may be increased.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.09/428,169 filed Oct. 27, 1999, now U.S. Pat. No. 6,296,132.

FIELD OF THE INVENTION

The invention relates to a dumpster for collecting, containing andcontrolling solid waste at a refuse collection site. More particularly,the invention is a universal dumpster adapted for use with both a frontloading and a roll-off refuse collection truck.

BACKGROUND OF THE INVENTION

Proper collection, containment, control, transportation and disposal ofsolid waste are necessary for protecting public health and safety andfor promoting a clean environment. Containers, commonly known asdumpsters, that hold large quantities of solid waste generated atmultifamily residential, institutional, commercial, industrial, andconstruction sites, are an important tool in the management of solidwaste.

There are at least two types of dumpsters for handling solid waste, the“front loader” dumpster and the “rear loader” dumpster. Present dumpsterdesigns incorporate several common features including: a floor, sidewalls, and end walls which together define an interior compartment;openings through which solid waste is placed into the interiorcompartment; openings through which the solid waste is discharged out ofthe interior compartment; and means for supporting the dumpster whilethe solid waste is being discharged.

The front loader type dumpster is typically used at multifamilyresidential and light commercial sites and is provided with sleevesfixed to the exterior of the side walls to receive the lifting arms of afront loading truck. The front loading truck approaches the front loaderdumpster and positions the arms of the truck within the sleeves of thecontainer. The driver then activates a hydraulic system which lifts thedumpster over the cabin of the truck and rotates it to a substantiallyinverted position to discharge the solid waste into a larger containeron the back of the truck, generally referred to as a hopper. Next, thedriver lowers the empty dumpster and withdraws the lifting arms of thefront loading truck from the sleeves. The driver may then activate acompactor in the hopper to compact the solid waste and thereby increasethe amount of solid waste that the hopper can accommodate. The frontloading truck then travels to the location of the next front loaderdumpster to repeat the procedure until the hopper is full. Once thehopper is full, the front loading truck travels to a disposal site, suchas a landfill, to dispose of the solid waste.

The rear loader type dumpster is larger than a front loader typedumpster and is typically used at heavy commercial, industrial andconstruction sites. Rather than being emptied into the hopper of a frontloading truck, the rear loader dumpster is pulled onto the bed of aroll-off truck and transported to the disposal site. A typical roll-offtruck is equipped with a winch and roller system which positions thedumpster onto the bed of the truck for transportation to the disposalsite. Once at the disposal site, the bed and dumpster are tilted so thatthe solid waste is discharged through one or more rear doors provided inthe end wall of the dumpster, much like a dump truck. After beingemptied, the rear loader dumpster is returned to the same or a differentrefuse collection site.

Utilizing different types of dumpsters which each require a differentmethod of discharging the solid waste reduces both the costeffectiveness and the efficiency of solid waste collection. Conventionalfront loader type dumpsters are relatively small and are not providedwith a door in an end wall of the dumpster. Furthermore, because thesolid waste in a conventional front loader dumpster must be dischargedthrough an opening in the top of the dumpster, it cannot be emptied by aroll-off truck. Conventional rear loader type dumpsters are wider thanfront loader type dumpsters and are not provided with sleeves. As such,a rear loader dumpster cannot be emptied by a front loading truck.Accordingly, solid waste collection would be more cost effective andefficient if the two types of dumpsters could be combined into a singleuniversal dumpster which can be emptied by either a front loading truckor a roll-off truck.

A major environmental concern is the accidental dispersal of solid wastefrom a front loader dumpster while the solid waste is being dischargedinto the hopper of the front loading truck. For example, a sudden gustof wind may disperse some of the solid waste onto the ground surroundingthe front loading truck as the front loader dumpster is being emptied.Front loader dumpsters are discharged at refuse collection sites thatare typically located in areas where people live and work. Thus, thesolid waste that is accidentally dispersed has a negative impact on boththe public health and safety and the environment.

Conventional designs for front loader dumpsters pose additional safetyconcerns. The sleeves of a front loader dumpster that engage the liftingarms of a front loading truck are typically welded onto the exteriorsurface of the side walls of the dumpster. Because the solid waste in aconventional front loader dumpster is discharged through an opening inthe top, the dumpster must be completely inverted to discharge all ofthe solid waste from the interior compartment. Completely inverting thedumpster induces shock stresses on the welds holding the sleeves to theside walls because the weight of the dumpster suddenly shifts from thetop of the sleeves to the bottom of the sleeves as the dumpster isinverted. Over time, the welds holding the sleeves to the side walls canweaken and ultimately break from repeated emptying of the dumpster. As aresult, the dumpster could fall onto the front loading truck as it isbeing inverted to discharge the solid waste, potentially injuringworkers or passersby.

In addition to posing a safety hazard, the shock stresses induced on thesleeve welds reduce the efficiency of front loading trucks. The liftingcapability of late model front-loading trucks usually exceeds the weightcapacity of a front loader dumpster. However, because of the danger ofthe sleeves breaking away from the side walls, the usable volume of afront loader dumpster is limited by a safety factor. If front loaderdumpsters were provided with doors in one of the end walls fordischarging solid waste, they would not have to be completely invertedto discharge all of the solid waste from the interior compartment of thedumpster. Eliminating the need to completely invert the dumpster wouldeliminate the shock stresses on the welds holding the sleeves to theside walls induced by the sudden shifting of the weight of the dumpsteron the sleeves. As a result, dumpsters capable of containing a largervolume of solid waste could be utilized with front loading trucks.

For the foregoing reasons, it is apparent that a need exists for auniversal dumpster that can be emptied by either a front loading truckor a roll-off truck. A need also exists for a universal dumpster thatminimizes, and preferably eliminates, the accidental dispersal of solidwaste into the environment during discharge of the solid waste into thehopper of a front loading truck. Finally, there exists a need toincrease both the safety of front loader dumpsters and the efficiency offront loading trucks.

SUMMARY OF THE OBJECTS OF THE INVENTION

Accordingly, it is a principal object of the present invention toprovide a universal dumpster that is designed and constructed in such away that it may be emptied by either a front loading truck or a roll-offtruck.

It is a further object of the present invention to provide a universaldumpster that minimizes the environmental damage caused by theaccidental dispersal of solid waste during discharge of the solid wasteinto the hopper of a front loading truck.

It is a further object of the present invention to provide a universaldumpster that is designed and constructed to be emptied by a frontloading truck without inducing shock stresses on the welds which holdthe sleeves to the side walls of the dumpster.

It is a further object of the present invention to provide a universaldumpster that is designed and constructed to be emptied by a frontloading truck without exerting excessive forces on the lifting arms of aconvention front loading refuse collection vehicle at the beginning ofthe lifting process.

It is a further object of the present invention to provide a universaldumpster that has an expandable volume.

It is a further object of the present invention to provide a universaldumpster having sufficient lids and doors conveniently located on thedumpster so that solid waste may be placed in all areas of the interiorcompartment of the dumpster.

SUMMARY OF THE INVENTION

The above objects and others are achieved by a universal dumpsterconstructed in accordance with the present invention. A universaldumpster according to this invention includes a floor having interiorand exterior surfaces. A pair of side walls extend upwardly andgenerally perpendicularly from the floor. Likewise, a pair of end wallsextend upwardly and generally perpendicularly from the floor. The endwalls are also generally perpendicular to and attached to the sidewalls. The floor, side walls and end walls together define an interiorcompartment for collecting and containing solid waste. A sleeve is fixedto each side wall to engage the pickup arm of a conventional frontloading refuse collection vehicle. At least one of the end walls of thedumpster includes at least one door which is movable between a firstfully closed position and a second fully opened position which exposesan opening through the end wall for depositing solid waste into thedumpster and discharging the solid waste from the dumpster.

In one preferred embodiment of the invention, the end wall is formed bya downwardly opening lower door hingedly attached to the floor andhaving a front panel and a pair of side panels. The front panel and theside panels form a discharge chute when the lower door is in the secondfully opened position. In another preferred embodiment, the end wall isformed by a pair of front doors that are movable between a first fullyclosed position and a second fully opened position. In the fully openedposition, the doors form a discharge chute. Each door is hingedlyattached to one of the side walls and has a floor panel extending fromthe base of the door. In another preferred embodiment, the end wall isformed by a pair of front doors that are hingedly attached to atelescoping discharge chute. The telescoping discharge chute is formedby a floor ramp extension panel and side wall extension panels extendingupwardly and generally perpendicularly from the floor ramp extensionpanel. The telescoping discharge chute is attached to the dumpster by atleast one telescoping rod.

In addition, the dumpster may be constructed with or without a lid. Alid for a dumpster according to this invention is formed by at least onedoor which is movable between a first fully closed position and a secondfully opened position which allows access to the interior compartment ofthe dumpster for depositing solid waste. Likewise, at least one of theside walls of the dumpster may be provided with a door that allowsaccess to the interior compartment of the dumpster for depositing solidwaste. In yet another preferred embodiment, the dumpster may include atleast two wheels attached to the floor of the dumpster and a removabletrailer hitch. The wheels and the trailer hitch permit the dumpster tobe moved to a location that is accessible to a conventional refusecollection vehicle. In yet another preferred embodiment, the dumpstermay include a pair of movable sleeves for reducing the forces exerted onthe lifting arms of a conventional front loading refuse collectionvehicle at the beginning of the lifting process, thereby furtherincreasing the capacity of the dumpster.

BRIEF DESCRIPTION OF THE DRAWINGS

In view of the aforementioned objects and others, which will morereadily appear as the nature of the invention is better understood, theinvention consists in the novel combination and arrangement of partshereinafter more fully described, illustrated and claimed with referencebeing made to the accompanying drawings in which:

FIG. 1 is a perspective view of a preferred embodiment of a universaldumpster according to the invention as viewed from the front of thedumpster.

FIG. 2 is a partial perspective view of the universal dumpster of FIG. 1with the discharge chute shown in the fully opened position.

FIG. 3A is a partial sectional view of the universal dumpster of FIG. 1,taken in the direction indicated by the line 3—3 in FIG. 1, with phantomlines indicating the movement of the upper door in the end wall and oneof the lid doors from their fully closed positions to their fully openedpositions.

FIG. 3B is a partial sectional view of the dumpster of FIG. 2 taken inthe direction indicated by the line 3—3 in FIG. 1.

FIG. 4 is a perspective view of the universal dumpster of FIG. 1 asviewed from the rear of the dumpster.

FIG. 5A is a partial perspective view of the universal dumpster of FIG.4 with the small inset doors shown in the opened position.

FIG. 5B is a partial perspective view of the universal dumpster of FIG.4 with the large rear doors shown in the opened position.

FIG. 6 is an environmental view of the universal dumpster of FIG. 1illustrating the lifting arms of a conventional front loading truckengaging the sleeves of the dumpster.

FIG. 7 is an environmental view of the universal dumpster of FIG. 1illustrating the dumpster being lifted and emptied through the frontdoors into the hopper of a conventional front loading truck.

FIG. 8A is an environmental view of the universal dumpster of FIG. 1illustrating the dumpster being tilted and emptied through the frontdoors by a conventional roll-off truck.

FIG. 8B is an environmental view of the universal dumpster of FIG. 1illustrating the dumpster being tilted and emptied through the reardoors by a conventional roll-off truck.

FIG. 9 is a partial elevation view and a partial sectional view ofanother preferred embodiment of a universal dumpster according to theinvention.

FIG. 10 is a sectional view of the universal dumpster of FIG. 9 taken inthe direction indicated by the line 10—10 in FIG. 9.

FIG. 11 is an end view of the universal dumpster of FIG. 9 taken in thedirection indicated by the line 11—11 in FIG. 9.

FIG. 12 is a perspective view of another preferred embodiment of auniversal dumpster according to the invention as viewed from the frontof the dumpster.

FIG. 13 is a perspective view of an alternate embodiment of theuniversal dumpster of FIG. 12.

FIG. 14 is an environmental view of the universal dumpster of FIG. 12illustrating the dumpster being pulled from the rear onto a conventionalroll-off truck for transportation to a disposal site.

FIG. 15 is a partial perspective view of another preferred embodiment ofa universal dumpster according to the invention as viewed from the frontof the dumpster.

FIG. 16 is a partial perspective view of the universal dumpster of FIG.15 with the front doors shown in the opened position.

FIG. 17 is a partial sectional view of the universal dumpster of FIG. 15taken in the direction indicated by the line 17—17 in FIG. 15.

FIG. 18 is a partial sectional view of the universal dumpster of FIG. 15taken in the direction indicated by the line 18—18 in FIG. 17.

FIG. 19 is a partial perspective view of another preferred embodiment ofa universal dumpster according to the invention as viewed from the frontof the dumpster.

FIG. 20 is a partial perspective view of the universal dumpster of FIG.19 with the front doors shown in the fully opened position and thetelescoping floor and telescoping side wall extensions shown in thefully extended position.

FIG. 21 is a partial sectional view of the universal dumpster of FIG. 19taken in the direction indicated by the line 21—21 in FIG. 19.

FIG. 22 is a partial sectional view of the universal dumpster of FIG. 19taken in the direction indicated by the line 22—22 in FIG. 21.

FIG. 23 is a perspective view of another preferred embodiment of auniversal dumpster according to the invention as viewed from the frontof the dumpster.

FIG. 24 is an exploded view of the universal dumpster of FIG. 23 withthe discharge chute shown in the opened position.

FIG. 25 is a perspective view of another preferred embodiment of auniversal dumpster according to the invention.

FIG. 26 is a perspective view of another preferred embodiment of auniversal dumpster according to the invention as viewed from the frontof the dumpster.

FIG. 27 is an environmental view of the universal dumpster of FIG. 26illustrating the lifting arms of a conventional front loading truckengaging the sleeves of the dumpster.

FIG. 28 is an environmental view of the universal dumpster of FIG. 26illustrating the dumpster being lifted from the ground by the liftingarms of a conventional front loading truck.

FIG. 29 is an environmental view of the universal dumpster of FIG. 26illustrating the dumpster being emptied through the front doors into thehopper of a conventional front loading truck.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A number of preferred embodiments of the present invention will bedescribed more fully hereinafter. However, the invention should not beconstrued as being limited to the embodiments described herein. Rather,it is intended that the invention be construed broadly to encompass anyand all embodiments of a dumpster having the disclosed features, orequivalents thereof, which are within the skill of an ordinary person inthe relevant art. In the description, like reference numerals designatelike or corresponding parts throughout the several figures. It is to bealso understood that such terms as “front”, “rear”, “top”, “floor”,“side”, and “end” are used in the description for purposes of locatingone element relative to another and are not to be construed as limitingterms. Finally, it should be understood that the illustrations providedin the figures are for the purpose of describing various preferredembodiments of the invention, and thus, are not intended to limit thescope of the invention in any manner.

Referring now to the accompanying figures, the invention is a largecontainer, hereinafter referred to as a dumpster, indicated generally at30, for the efficient collection, containment, and control of solidwaste material. In the broadest sense, the dumpster 30 comprises a floor40, opposed side walls 50, and opposed end walls 60. The floor 40, sidewalls 50 and end walls 60 together define an interior compartment of thedumpster 30 for collecting and containing the solid waste. Dumpster 30is generally rectangular, but may be constructed to any size and shapewhich will contain the solid waste efficiently and accommodate theconventional apparatus for discharging the solid waste from thedumpster. While dumpsters are generally made of a rigid metal, such assteel, the dumpster 30 of the present invention may be made of any rigidand durable material. The floor 40, the side walls 50 and the end walls60 are preferably thin and lightweight to permit conventional refusecollection vehicles to lift and transport as much solid waste aspossible. However, the dumpster 30 must also be strong and durableenough to withstand repeated lifting, transportation and discharge ofthe solid waste, and prolonged exposure to the elements.

The floor 40 comprises floor plate 42 that is raised above the ground bysupport feet 44 attached to the underside of the floor plate 42. Atleast one hook 46 is also attached to the floor plate 42 adjacent to atleast one of the end walls 60 for pulling the dumpster 30 onto aroll-off truck R, as illustrated in FIG. 14. The hook 46 is engaged by aconventional winch which pulls the dumpster 30 onto the bed of theroll-off truck R. As the dumpster 30 is pulled onto the bed of roll-offtruck R, the support feet 44 engage rollers which assist the winch inpositioning the dumpster 30 on the truck R and support the dumpster 30during transportation. The support feet 44 and hook 46 may be attachedto the floor plate 42 by any conventional means, such as welding, whichprovides a rigid and durable attachment. The floor 40 further comprisesa ramp 48 that slopes upwardly from a medial point on the top side ofthe floor plate 42 in the direction of one of the end walls 60 tofacilitate emptying of the solid waste, as will be describedhereinafter.

The side walls 50 extend upwardly and generally perpendicularly from thefloor 40. Preferably, at least one of the side walls 50 has an opening52 formed therein (FIG. 3A) which provides access to the interiorcompartment of the dumpster 30 for depositing the solid waste. Morepreferably, a door 54 may be provided that is movable from a fullyclosed position covering the opening 52 to a fully opened positionexposing the opening 52. The door 54 may be provided with a handle 55 tofacilitate movement between the fully closed position and the fullyopened position. The door 54 is preferably biased in the closed positionsince it is desirable to cover the opening 52 while the dumpster 30 isbeing transported or emptied. As is shown in FIGS. 9, 10 and 11, theside walls 50 may comprise angled side portions 51 which taper inwardlyto form a neck having a width narrower than that of the remainder of theinterior compartment of the dumpster 30. The neck allows a dumpster 30having the width of a conventional rear loading dumpster to be emptiedinto the hopper of a conventional front loading truck F.

A pickup sleeve 56 is fixed to each side wall 50. The sleeves 56 areconstructed to accommodate the lifting arms A of a conventional frontloading truck F (FIG. 6). In some preferred embodiments, the pickupsleeves 56 are positioned on the exterior surface of the side walls 50adjacent the floor 40 of the dumpster 30 and flush with one of the endwalls 60 of the dumpster 30 (FIG. 1-4, 6-8B, 15-16, 19-20). In otherpreferred embodiments, the sleeves 56 are positioned on the interiorsurface of the side walls 50 in the space between the floor ramp 48 andthe floor plate 42 (FIGS. 9-11, 12-13, 23-24). The pickup sleeves 56 maybe fixed to the side walls 50 by any conventional means, but preferablyare welded to the exterior or interior surface of the side walls 50.

As best shown in FIGS. 1 and 2, in a preferred embodiment of theinvention at least one of the end walls 60 is formed by an upwardlyopening upper door 62 and downwardly opening lower door 64. Each of thedoors, 62, 64 is movable between a fully closed and a fully openedposition. The upwardly opening upper door 62 hangs between the ends ofthe side walls 50 from a lateral hinge 61. Handle 63 enables a user toopen upper door 62 for the purpose of placing solid waste in thedumpster 30. Upper door 62 is biased in the closed position by gravity.However, hinge 61 may also be provided with a torsion spring (not shown)for biasing upper door 62 in the closed position. Downwardly openinglower door 64 comprises a front panel 64 a and side panels 65 thatoverlap the exterior surface of side walls 50 when the lower door 64 isin the fully closed position. The lower door 64 is biased in the closedposition by a pre-tensioned torsion spring 66 located along the hingeline formed between the lower door 64 and the floor 40 of the dumpster30. Detent latches 67 may be attached to the exterior surface of theside walls 50 to insure that the lower door 64 remains in a closedposition until the dumpster 30 is lifted and tilted by a front loadingtruck F to be emptied.

When the dumpster 30 is tilted, the lower door 64 opens automaticallyunder the weight of the solid waste in the interior compartment of thedumpster 30. A discharge chute, for directing the solid waste from theinterior compartment of the dumpster 30 into the hopper H of the frontloading truck F (FIG. 7), is formed by the front panel 64 a and the sidepanels 65 of the fully opened lower door 64. The upper door 62 alsoopens when the dumpster 30 is lifted and tilted into position foremptying. Preferably, when the lower door 64 is in the fully openedposition, the angle of the front panel 64 a relative to the floor 40 ofthe dumpster 30 corresponds to the angle of the ramp 48 relative to thefloor 40. Thus, the front panel 64 a forms a straight line with the ramp48, as shown in FIG. 3B. Preferably, at least one stop 68 is provided onthe dumpster 30 to prevent the lower door 64 from opening beyond thepoint where the front panel 64 a and the ramp 48 form a straight line.The stop 68 may be fixed to the floor 40 of the dumpster 30, as shown inFIG. 1, or may be fixed at any other convenient location on the dumpster30.

A rear view of the same preferred embodiment of the invention is shownin FIGS. 4, 5A and 5B. In the rear view it is apparent that at least oneof the end walls 60 is formed by a pair of large rear doors 70 attachedto the side walls 50 by opposed vertical hinges 72. Preferably, each ofthe large rear doors 70 is biased in the closed position by apre-tensioned spring located along the hinge line formed between theside wall 50 and the end wall 60.

Preferably, each of the rear doors 70 has an opening 73 formed therein(FIG. 5A) for providing access to the interior compartment of thedumpster 30 to deposit the solid waste. The opening 73 is covered by asmall inset door 74 that is movable between a fully closed position anda fully opened position. Preferably, hinges 75 provided between the reardoors 70 and the inset doors 74 are angled relative to vertical to biasthe inset doors 74 in the closed position. A handle 76 may also beprovided to assist in opening the inset door 74.

The preferred embodiment of the universal dumpster 30 described abovehas at least three advantages. First, the open upper door 62 and theopen lower door 64 define a funnel that directs the solid waste into thehopper H of the front loading truck F. The funnel prevents the solidwaste from being accidentally dispersed into the surrounding environmentas the dumpster 30 is being emptied into the hopper H of the frontloading truck F, as illustrated in FIG. 7. Second, because the dumpster30 is emptied through an end wall 60 instead of the top, the dumpster 30empties with a reduced lifting angle L relative to horizontal. Morespecifically, the front loading truck F does not have to rotate thedumpster 30 to a substantially inverted position as is required with aconventional front loader dumpster. Accordingly, the lifting angle Lgenerates little or no torque reversal. As a result, the dumpster 30 maybe made considerably larger than a conventional front loader dumpster.Third, the universal dumpster 30 of this preferred embodiment may beemptied from either end by a conventional roll-off truck R, asillustrated in FIGS. 8A and 8B.

Another preferred embodiment of the invention is shown in FIGS. 9-11. Aspreviously mentioned, angled side portions 51 of side walls 50 allowdumpster 30 having the width of a conventional rear loading dumpster tobe emptied into the hopper H of a conventional front loading truck F.This preferred embodiment utilizes pick up sleeves 56 positioned on theinterior surface of side walls 50 in the space between the ramp 48 andthe floor plate 42. In order to accommodate the sleeves 56, the spacebetween the ramp 48 and the floor plate 42 is enlarged by the additionof a ramp portion 48 a. Ramp portion 48 a is positioned at less of anangle relative to the floor 40 than that of ramp 48. Preferably, whenthe downwardly opening lower door 64 is in the fully opened position,the angle of the front panel 64 a relative to the floor 40 correspondsto the angle of the ramp portion 48 a relative to the floor 40. Sidepanels 65 of lower door 64 overlap the interior surface of side walls 50of the dumpster 30.

Another preferred embodiment of the invention is shown in FIGS. 12 and13. This preferred embodiment also utilizes a downwardly opening lowerdoor 64 comprising side panels 65 that overlap the interior surface ofside walls 50 of the dumpster 30.

Another preferred embodiment of the invention is shown in FIGS. 15-18.In this preferred embodiment, at least one of the end walls 60 of thedumpster 30 is formed by a pair of large front doors 80 attached to theside walls 50 by vertical hinges 82 such that the doors 80 are movablebetween a fully closed position and a fully opened position. Preferably,each door 80 is biased in the closed position by one or morepre-tensioned torsion springs 83 located along the hinge line formedbetween the side wall 50 and the end wall 60. Each door 80 comprises anarcuate floor panel 84 that is attached to the base of the door 80 at anangle relative to the floor 40 that corresponds to the angle of the ramp48 relative to the floor 40 of the dumpster 30. When the doors 80 are inthe fully opened position, the floor panels 84 overlap one another toform an extension of the ramp 48. In the closed position, the floorpanels 84 retract into the open space 85 between the ramp 48 and thefloor plate 42, as best shown in FIG. 17. In the fully opened position,the ramp 48, doors 80 and floor panels 84 define a funnel fordischarging the solid waste from the interior compartment of thedumpster 30, as previously described.

Another preferred embodiment of the invention is shown in FIGS. 19-22.In this embodiment, at least one of the end walls 60 is formed by a pairof large front doors 90. The doors 90 are attached to side wallextension panels 92 by vertical hinges 94 such that the doors 90 aremovable between a fully closed position and a fully opened position.Preferably, each door 90 is biased in the closed position by one or morepre-tensioned torsion springs 95 located along the hinge line formedbetween the side wall extension panel 92 and the door 90. Each side wallextension panel 92 is attached along its base to a floor ramp extensionpanel 96. The side wall extension panels 92 are connected to telescopingrods 97 which slide between a fully extended position and a fullyretracted position to allow the side wall extension panels 92 and thefloor ramp extension panel 96 to alternatively telescope outwardly fromthe dumpster 30 and retract back into the interior compartment of thedumpster 30. The telescoping rods 97 are mounted for movement in sleeves98 that are fixed to the exterior surface of side walls 50 of thedumpster 30. Preferably, each of the telescoping rods 97 is biased inthe fully retracted position by a coil spring 99. The end of the rod 97is provided with a stop 97 a to prevent the side wall extension panel 92from extending too far. In the fully retracted position, the side wallextension panels 92 overlap the interior surface of the side walls 50and floor ramp extension panel 96 overlaps the interior surface of theramp 48 so that the dumpster 30 is available for receiving solid wastein the interior compartment. As the dumpster 30 is tilted for emptying,the side wall extension panels 92 and the floor ramp extension panel 96slide outwardly from the dumpster 30 as a unit. Once the side wallextension panels 92 and the floor ramp extension panel 96 are fullyextended, the doors 90 open outwardly under the weight of the solidwaste being discharged from the dumpster 30. Together, the side wallextension panels 92, the floor ramp extension panel 96 and the doors 90form a telescoping discharge chute for guiding the solid waste out ofthe interior compartment of the dumpster 30.

Preferably, dumpster 30 has a removable lid 100 which can be opened toallow access to the interior compartment of the dumpster 30 from aboveand can be closed to prevent refuse from blowing out of the dumpster 30during transportation and during discharge of the solid waste from theinterior compartment of the dumpster 30. One embodiment of the lid 100comprises a pair of hinged top doors 102. The top doors 102 may behinged at the end walls 60 or may be hinged at a medial location betweenthe end walls 60 of the dumpster 30. Each top door 102 of the lid 100opens upwardly to allow access to the interior compartment of thedumpster 30 to deposit the solid waste. One or both top doors 102 of thelid 100 may also be removed entirely to allow the dumpster 30 to beutilized, for example, at a construction site to collect and containlarge articles of debris, such as building materials. The dumpster 30may be constructed without any lid 100 as shown in FIG. 12. However, thelack of a lid 100 increases the likelihood that solid waste will beaccidentally dispersed during discharge of the solid waste into thehopper H of a front loading truck F or during transportation by aroll-off truck R. In another preferred embodiment, shown in FIG. 13, thelid 100 of the dumpster 30 comprises a pair of top doors 106 hingedalong the side walls 50 of the dumpster 30. This preferred embodimentallows use of the dumpster 30 at a construction site, or other sitewhere large articles of solid waste are generated, without having toremove any portion of the lid 100.

In another preferred embodiment, shown in FIGS. 23 and 24, the dumpster30 comprises a removable lid 110 for expanding the usable volume of thedumpster 30. The lid 110 comprises end walls 112, side walls 114 and apair of top doors 116. A retaining leg 118 provided at each bottomcorner of the lid 110 cooperates with a hollow comer post 120 providedat each upper comer of the dumpster to secure the lid 110 on thedumpster 30. A removable end wall cross bar 122 is also provided tosupport the end walls 60 of the dumpster 30 when the lid 110 is not inuse. The cross bar 122 may be removed to prevent solid waste fromcatching between the hinged lower door 64 and the hinged end wall 112during discharge when the lid 110 is in use. The end walls 112 and theside walls 114 of the lid 110 may be adapted for use with any of thepreferred embodiments of the invention disclosed herein.

In some situations, it may be convenient to locate a dumpster 30 in aplace that is not readily accessible to either a front loading truck For a roll-off truck R. To accommodate these situations, the dumpster 30could be fitted with wheels 130 and a removable trailer hitch 132 asshown in FIG. 25. The wheels 130 and removable trailer hitch 132 permitthe dumpster 30 to be moved to a location that is accessible to therefuse collection trucks so that the dumpster 30 may be emptied.

In yet another preferred embodiment, shown in FIGS. 26-29, the dumpster30 reduces the forces exerted on the lifting arms A of a conventionalfront loading truck F. The dumpster 30 is substantially identical to thedumpster shown in FIGS. 1-8B except that the floor 40 does not compriseramp 48 sloping upwardly from a medial point on the top side of thefloor plate 42 in the direction of one of the end walls 60. As a result,the torsion spring 66 is located nearer to the ground. Accordingly, thefront loading truck F is not required to rotate the dumpster 30 quite asfar to discharge solid waste from the interior compartment of thedumpster 30 into the hopper H of the front loading truck F (FIG. 29). Inaddition, the pickup sleeves 156 are rotatably mounted to the exteriorsurface of the side walls 50 adjacent the floor 40 of the dumpster 30.The pickup sleeves 156 may be rotatably mounted to the side walls 50 inany known manner. As shown, each pickup sleeve 156 comprises atriangular-shaped pivot 160 mounted on a cylindrical trunnion pin 162projecting outwardly from the side wall 50. Sleeves 156 areinterconnected by a relatively large diameter sleeve bar 164 extendingtransversely between the side walls 50 such that sleeves 156 and sleevebar 164 form a generally U-shaped lifting tongue.

As previously described, the sleeves 156 are constructed to engage thelifting arms A of a conventional front loading truck F (FIG. 27).However, because the sleeves 156 are rotatably mounted to the side walls50, the sleeves 156 will be lying on the ground when the lifting arms Ainitially engage the sleeves 156 of the dumpster 30 (FIG. 27). As thelifting arms A fully engage the sleeves 156 and begin to lift thedumpster 30, the sleeves 156 rotate about the pivots 160 on thetrunnions 162. As a result, the dumpster 30 is dragged in the directionof the front loading truck F until the sleeve bar 164 contacts feet 44on the underside of the floor 40 of the dumpster 30. Rotation of thesleeves 156 is terminated once the dumpster 30 has been lifted by thefront loading truck F approximately sixty degrees relative tohorizontal, as depicted by the broken lines in FIG. 28. The frontloading truck F continues to lift the dumpster 30 upwardly andrearwardly so that the dumpster 30 is substantially horizontal above thefront loading truck F, as depicted by the broken lines in FIG. 29.

It should be noted that because the sleeves 156 are rotatably mounted tothe side walls 50, the elevation of the dumpster 30 above the frontloading truck F is reduced compared to the elevation of the dumpster 30,as depicted in FIG. 7. Accordingly, the center of gravity of thedumpster 30 is closer to the front loading truck F at both the beginningand during the initial stage of the lifting process, and less force istherefore exerted on the lifting arms A. As a result, the capacity ofthe dumpster 30 may be increased somewhat. The lifting arms A continueto lift and tilt the dumpster 30 rearwardly approximately 105 degreesuntil the weight of the solid waste in the interior compartment of thedumpster 30 automatically opens the lower door 64 against the torsionspring 66, as previously described. The lower dumping position, asdepicted by the solid lines in FIG. 29, permits the solid waste in theinterior compartment of the dumpster 30 to be discharged deeper into thehopper H of the front loading truck F.

It is to be understood that the forgoing description and specificembodiments shown herein are merely illustrative of the best mode of theinvention and the principals thereof, and that various modifications andadditions may be made by those skilled in the art without departingunnecessarily from the spirit and scope of the invention, which isintended to be limited only by the scope of the appended claims.

That which is claimed:
 1. A dumpster for collecting and dischargingsolid waste comprising: a floor having interior and exterior surfaces; apair of side walls having interior and exterior surfaces, each of saidside walls extending upwardly from said floor and attached thereto; apair of end walls having interior and exterior surfaces, each of saidend walls extending upwardly from said floor and attached to said floorand said side walls; said floor, said side walls and said end wallsdefining an interior compartment for collecting the solid waste therein;a pair of sleeves, each of said sleeves rotatably mounted to theexterior surface of one of said side walls and having an elongateopening formed therein sized to accommodate the lifting arms of a frontloading refuse collection vehicle, said sleeves being rotatably mountedto permit the lifting arms to lift and tilt the dumpster to dischargethe solid waste from the interior compartment without inverting thedumpster; and a sleeve bar extending transversely between said sidewalls and interconnecting said sleeves such that said sleeves and saidsleeve bar form a generally U-shaped lifting tongue.
 2. A dumpsteraccording to claim 1 wherein each of said sleeves comprises a pivotmounted on a trunnion pin secured to and projecting outwardly from oneof said side walls.
 3. A dumpster according to claim 1 wherein saidfloor further comprises a pair of elongate support feet, each of saidsupport feet fixed to the exterior surface of said floor between saidend walls and having a bottom surface for contacting said sleeve bar. 4.A dumpster according to claim 1 wherein at least one of said end wallshas an opening therethrough and comprises a lower door hingedly attachedto said floor, said lower door movable between a first fully closedposition and a second fully opened position to discharge the solid wastefrom the interior compartment of the dumpster.
 5. A dumpster accordingto claim 4 wherein said lower door moves to the second fully openedposition automatically under the weight of the solid waste in theinterior compartment defined by said floor, said side walls and said endwalls when the dumpster is tilted to discharge the solid waste.
 6. Adumpster according to claim 4 wherein said lower door is biased in thefirst fully closed position.
 7. A dumpster according to claim 4 whereinsaid at least one end wall further comprises an upper door pivotallyconnected to said side walls.
 8. A dumpster according to claim 1 whereinat least one of said side walls has at least one opening therethroughand comprises at least one movable door, said at least one door movablebetween a first fully closed position and a second fully opened positionto provide access through the opening to the interior compartmentdefined by said floor, said side walls and said end walls.
 9. A dumpsteraccording to claim 1 wherein said floor further comprises at least onehook fixed to said floor adjacent one of said end walls for engaging awinch of a roll-off refuse collection vehicle.
 10. A dumpster forcollecting and discharging solid waste comprising: a floor havinginterior and exterior surfaces; a pair of side walls having interior andexterior surfaces, each of said side walls extending upwardly from saidfloor and attached thereto; a pair of end walls having interior andexterior surfaces, each of said end walls extending upwardly from saidfloor and attached to said floor and said side walls; said floor, saidside walls and said end walls defining an interior compartment forcollecting the solid waste therein; a pair of sleeves, each of saidsleeves having an elongate opening formed therein sized to accommodatethe lifting arms of a front loading refuse collection vehicle, saidsleeves movable relative to said floor, said side walls and said endwalls such that the dumpster is dragged in the direction of the frontloading refuse collection vehicle when the lifting arms engage saidsleeves and lift the dumpster, said sleeves being movable to permit thelifting arms to lift and tilt the dumpster to discharge the solid wastefrom the interior compartment without inverting the dumpster; and asleeve bar extending transversely between said side walls andinterconnecting said sleeves such that said sleeves and said sleeve barform a generally U-shaped lifting tongue.
 11. A dumpster according toclaim 10 wherein each of said sleeves comprises a pivot mounted on atrunnion pin secured to and projecting outwardly from one of said sidewalls.
 12. A dumpster according to claim 10 wherein said floor furthercomprises a pair of elongate support feet, each of said support feetfixed to the exterior surface of said floor between said end walls andhaving a bottom surface for contacting said sleeve bar.
 13. A dumpsteraccording to claim 10 wherein at least one of said end walls has anopening therethrough and comprises a lower door hingedly attached tosaid floor, said lower door movable between a first fully closedposition and a second fully opened position to discharge the solid wastefrom the interior compartment of the dumpster.
 14. A dumpster accordingto claim 13 wherein said lower door moves to the second fully openedposition automatically under the weight of the solid waste in theinterior compartment defined by said floor, said side walls and said endwalls when the dumpster is tilted to discharge the solid waste.
 15. Adumpster according to claim 13 wherein said lower door is biased in thefirst fully closed position.
 16. A method for reducing the force exertedon the lifting arms of a front loading refuse collection vehicle when adumpster is lifted to discharge solid waste, the method comprising thesteps of: providing a dumpster comprising: a floor having interior andexterior surfaces; a pair of side walls having interior and exteriorsurfaces, each of said side walls extending upwardly from said floor andattached thereto; a pair of end walls having interior and exteriorsurfaces, each of said end walls extending upwardly from said floor andattached to said floor and said side walls; said floor, said side wallsand said end walls defining an interior compartment for collecting thesolid waste therein; a pair of sleeves, each of said sleeves having anelongate opening formed therein sized to accommodate the lifting arms ofthe front loading refuse collection vehicle, said sleeves movablerelative to said floor, said side walls and said end walls; engagingsaid sleeves of the dumpster with the lifting arms of the front loadingrefuse collection vehicle; and a sleeve bar extending transverselybetween said side walls and interconnecting said sleeves such that saidsleeves and said sleeve bar form a generally U-shaped lifting tongue;and lifting and tilting the dumpster using the lifting arms of the frontloading refuse collection vehicle to discharge the solid waste from theinterior compartment without inverting the dumpster.
 17. A methodaccording to claim 16 wherein each of said sleeves comprises a pivotmounted on a trunnion pin secured to and projecting outwardly from oneof said side walls.
 18. A method according to claim 16 wherein saidsleeve bar contacts the exterior surface of said floor medially betweensaid end walls when the lifting arms of the front loading refusecollection vehicle lift the dumpster.